schaap



APPLICATION FILED MAR. 18, I918.

Patented Dec, 23, 1919.

3 SHEETSSHEET I.

. A. K. SCHAAP.

APPARATUS FOR MAKING PISTON RINGS.

APPLICATION FILED MAR. H3, 1918.

Patented Dec. 23, 1919.

- 3 SHEETSSHEET 2- GM... swim Y BY @33 7 ATTORNE A. K. SCHAAP.

APPARATUS FOR MAKING PISTON RINGS.

APPLICATION FILED MAR. 18, 1918- 1,325,659. Patented Dec. 23,1919.

3 SHEETSSHEET Ii- UNITED STATES PATENT oFmoE.

ALEXANDER K. scnaar, or BROOKLYN, New YORK.

APPARATUS FOR MAKING PISTON- RINGS.

Application filed March 18, 1918.

provide a piston ring which will at all times.

fit true and wear true and without binding in the position in which it is placed, and give a maximum of'efliciency while in use. This object is accomplished by the product of my invention which will now be more particularly set forth.

For a more particular description of my invention, reference is to be had to the accompanying drawings, forming a part hereof, in which.

Figure 1 is a plan view of a portion of a machine embodying my invention with the first out being taken.

tion of the ring just after the second out has been taken.

. Fig. 5 shows the apparatus and ring while the third cut is being taken, after the ring has been turned over.

. Fig. 6 shows the condition of the ring at the finish of the-cut.

Fig. 7 shows the apparatus taking the fourth cut.

Fig. 8 shows the condition of the ring when this out has been completed.

Fig. 9 is a sectional view, taken on the line 9-9, of Fig. 5, looking in the. directio of the arrows.

Fig. 10 is a plan view of the apparatus when ready to take the third out, parts being removed to more clearly reveal the structure. 7

Fig. 11 is a sectional view, taken on the line 111-11 of Fig. 5, looking in the direction of the arrows.

Figs. 12 and 13 show the compressing jacket used when putting therings on a Specification of Letters Patent.

Patented 1360.23, 1919.

Serial No. 222,992.

mandrel after they have been cut, as shown in the preceding figures, Fig. 12 being a sec tional view, taken substantially on the line 12l2 of Fig. 18, looking in the direction of the arrows. v

Figs. 14 and 15show a group of ringson a mandrel readyfor grinding.

Throughout the various views of the drawings, similar reference characters deslgnate simllar parts; It 1s not necessary to go 1nto the prelimlnary stages of the manufacture of a packing" ring, because they may be of any suitable kind and form no part of this invention. It is suflicient to say that the rings embodying my invention may be made from any suitable blanks,as a casing of the conventional form which is first placed in a sultable grinding machine and ground so as to have its flat faces made absolutely true and in parallel planes. Assuming the rings to be in this condition they are then placed on a suitable mandrel and turned and ground until they are a little too large, say about one hundred and fifty thousandths of an inch too large, depending upon the nature of the ring and the amount of finishing cut desired. Assuming the blanks to have'been thus prepared they are then ready for my improved apparatus and methods, and are treated as will now bedescribed.

The blank 1 is put in a chuck 2 of the milling machine 3 and clamped firmly by means of a suitable clamp 4.. This machine 3 has a milling cutter 5, which is in the nature of a saw, about 'j gth of an inch thick, and of any suitable diameter, say 2?; or 3 inches, and is mounted on a spindle 6, which is driven in the conventional way by any suitable means, not shown. This spindle 6 has its cutter 5 so placed with regard to the chuck 2 thatthis chuck may turn on a pivot 7 with its axis resting in the median plane of the cutter 5 and intersecting the axis of the spindle 6.when in'its mid-position. If this position of the pivot 7 is "not .obtained'the rings 1 will be defective and the defect willbe serious and defeat the purpose of this invention when this pivot 7 is substantially out of its true position.

The pivot 7 extends into a table 8, which has a reciprocating movement of the conventional kind, as is customary in milling machines. The table 8 reciprocates in the general direction of the median plane of the cutter 5'.

The clamp 4 may be made in any suitable way, and in the preferred embodiment of my invention, consists of a suitable bolt 9 which is screw-threaded into the table 8 and passes upwardly through the chuck 2. The bolt is provided with a suitable bar 10 whlch extends over the ring 1 (see Fig. 9) and under a suitable cap-screw 11 Where it may be secured with a free turning movement at one side and clear of the chuck 2.

The chuck 2 rests fiat on the bed 8 and turns on its pivot 7 and is provided with a circular opening 12 at its center, so that it will swing until limited by a washer 9 on the bolt 9, and the chuck 2 is also provided with a suitable collar 13 against which the ring 1 may rest under normal conditions and be securely held while being cut, as well as a handle 14 which is secured to it by any suitable means, as screws, which are preferably placed so that the handle 14 is diametrically opposite the pivot 7 and there is also mounted on this chuck a segmental plate 15 (see Fig. 10) which carries a suitable ton 1e 16 and this plate is locked in position %dy means of a set screw 17. The tongue 16 is so placed and shaped that it will lie in the cut of the ring 1 shown in Fig. 4, and fit snug within the same so as to support this ring in its true position and hold it true while it is receiving the third and fourth cuts.

The diameter of the hole 12 is such, when taken in connection with its position, that the handle 14 may be swung to the right of the vertical plane containing the axis of the spindle 6 to substantially 7 degrees, as shown in Fig. 1. The cut when so taken may be designated by the character 18. After this out 18 has been so made, a second cut is made after the handle 14 has been thrown to the left a like amount. The second cut engages the cut 18, as shown in Fig. 4, until it becomes what might be designated the cut 19 when the converging walls 20 and 21 are not parallel as are the walls of the cut 18. The foregoing description has been given for a ring substantially 4% inches in external diameter. The walls 20 and 21 are not quite in their ideal locations because of the thickness of the cutting tool 5. The ideal position would be the median plane of the cutting tool 5. This is not practical be cause the cutting tool must necessarily have suflicient thickness to make it strong enough to perform its functions." However, as the respective edges 20 and 21 are cut parallel with their respective ideal positions and equidistant therefrom, they sufiiciently approach the ideal positions to enable them to perform their functions properly. After the cut 19 is made the ring 1 is removed from the chuck 2 and then the part 15 is inserted, as shown in Fig. 10, With its tongue 16 adapted to enter and fit snug in the groove 19, when the ring 1 is again placed in the chuck 2. lVhile the ring 1 is out of the chuck 2, a new washer 9 is substituted which is substantially thirty thousandths of an inch larger.

The clamp 4 is released so as to enable the ring 1 to be either removed or shifted, and it is always tightened after the shifting or removal has taken place and the chuck and ring are in their proper respective positions. 'When the ring 1 is in the positions necessary for the third out it is taken, as shown in Fig. 5, with the handle 14 at the left instead of the right, and then the cut 22 appears, as shown in Fig. 6. After this out has been made the clamp 4 is released, the chuck shifted about 11 degrees and 27 minutes, because of the enlarged Washer 9 to the position shown in Fig. 7, when the clamp is again secured and then the finishing cut is made, as shown in Fig. 8, where the groove 23 appears and it is provided with the converging walls 24 and 25. These walls correspond to the walls 20 and 21 of the groove 19. Thereafter the ring may be removed from the chuck 2 and placed with a number of other rings, as shown in Figs.

12 and 13, in the jacket 26, which is then tightened by means of the bolts 27 until the joints of the rings are closed tight. These rings are then placed on a mandrel 28, in the conventional manner, as shown in Figs. 14 and 15, and ground to their correct diameters, after which they are finished and may be removed from the mandrel and used. When in use the edges 20 and 21 engage each other and so do the edges 24 and 25 and they engage so as to form a gastight joint. The depth of the cut 18 and the succeeding cuts is such that they extend only half way through the ring 1 so that when all the cuts are completed and the ends of each ring are brought together there is a snug fit of the parts which rub on each side median plane of the ring. From this it is apparent that the three engaging surfaces at each end of each ring engage with a sliding fit, which is true, or nearly so, for each position of the ring so that under all conditionsof service these ends engage with a gas-tight fit, which will prevent all leakage, and yet the ring is free to slide in a cylinder of irregular or varying diameter without losing the tight fit or binding or breaking.

Having thus described my invention, what I claim is:

1. In a machine of the class described, means for holding a blank ring so that a diagonal cut may be taken, means for shifting the ring after the first cut through an angle about a center under the axis of the cutter, and at or near the periphery of the ring and means for taking the first and second cuts.

2. In a machine of the class described, a rotary cutter, a table carrying a chuck which is adapted to be swung on an axis passing through the median plane of the cutter and at or near the periphery of the ring, and means for clamping a piston ring so that a cut may be taken When it is held in either of two positions of said chuck.

3. In a machine of the class described, a cutter having a median plane, a table having a feed in the direction of said plane, a pivotally mounted chuck adapted to be clamped in two positions With a pivot pass ing through said median plane and through the periphery of the ring being cut.

. 4. In a machine of the class described, a cutter having a median plane, a table adapted to be shifted in the directionnof said plane, a chuck pivotally mounted on said table With the axis of its pivot in said median plane and also in the periphery of a ring which is held by said chuck and cut by said cutter, a clamp adapted to hold said ring in said chuck, a tongue adapted to fit in said ring and give said ring a correct position With regard to said cutter and means for holding said tongue in place.

ALEXANDER K. SCHAAP. 

